Gravitational forces on humans play a fundamental role in biological development and physiological functioning of the body in both health and in several disease conditions. Systems and methods that counteract both physical as well as physiological stresses on the body are summarized in this application. Also described in this application are application of the same systems and methods to exert forces similar to gravitational forces on the body when such forces are desirable. Humans experience fatigue when they stay upright for extended periods, as compared to when sitting down on a chair or lying down on a bed, because various muscle groups have to work against gravitational force to maintain the upright body posture. The major weight-bearing regions of the body (e.g., the spine, the back and the buttocks, posterior region of thighs and feet) carry the load of significant portion of the body weight while a person is seated or in standing in an upright position. Prolonged periods of sitting in an office chair or in a car seat or even lying down on bed for long time (e.g., elderly in a long term care facility), often causes a significant pressure as well as shear forces on the weight-bearing regions. This often results in fatigue of the back muscles, stress and low productivity (e.g., in the office workers). Several conditions including chronic back pain due to poor posture, vertebral compression, sciatic pain due to pressed spinal nerves, pressure ulcers (e.g., as encountered in wheel chair-bound patients or in the elderly in long term care facilities) are some examples of consequences of the ailments that affect humans due to the gravitational forces acting on the weight-bearing regions of the body. Therefore, a significant need exists for innovative solutions to minimize the pressure on the weight-bearing regions of the body to increase comfort while seated or lying down and prevent the adverse effects on the weight-bearing regions of the body.
Patients with restricted ability to move, such as bed ridden patients, often loose bone density and muscle strength, as they do not exert forces against the body weight. Similar observations of loss of bone density, and muscle strength are noted in astronauts who spent prolonged time in the microgravity conditions. At present, there is no effective solution available to address these adverse effects on astronauts. Therefore, a significant need exists for preventing such adverse effects on people.
Gravitational forces also play a significant role in various disease conditions including hypertension, edema, gestational preeclampsia, diabetes, cardiovascular disorders, neurological conditions, motion sickness, various metabolic disorders associated with for example, increased body mass index, and the like. While effective therapeutic options are available for some of the conditions, the available treatment options for other conditions are either suboptimal or fraught with risks.